Machine for withdrawing predetermined batches of flat objects, such as envelopes or sheets of paper, from a continuously forming row

Abstract

 The machine comprises a conveyor (30) for advancing the objects (3) in a continuous row in which they are orientated vertically and transversely: a parting means is provided consisting of two elongate parallel elements (11′) and (11˝) which when alongside each other define a pointed rod (11), said rod (11) being disposed on a transverse axis passing through the row (2) of objects (3); means (10) insert the pointed end of said rod (11) axially through the row (2) of objects and means (20) move the two elongate elements (11′) and (11˝) together and apart to define a gap which separates an end segment (2′) of the row from the remaining row portion (2˝); gripper means (40) are also provided comprising two jaws (41) and (42) for gripping said end row segment (2′); after the rod (11) has been inserted through the row (2) and the two elements (11′) and (11˝) have been moved apart, the gripper means (40) are moved towards the upper surface of the conveyor (30) to insert one jaw (41) into said gap; the elements (11′) and (11˝) are then extracted from the row (2) and the jaws (41) and (42) are clamped against the row segment (2′).

Description

[0001] This invention relates to a machine for withdrawing predetermined batches of flat objects, typically envelopes or sheets of paper, from a continuously forming row.

[0002] Various types of machine are known for manufacturing envelopes or similar flat objects, which are then released onto an endless conveyor to form a continuous row in which the envelopes lie individually in succession in direct contact with each other in a substantially vertical transverse orientation on the upper surface of the conveyor.

[0003] For packaging purposes, these envelopes are currently transferred manually in batches comprising a predetermined number of envelopes into container boxes. To aid the operator, a device is provided to cyclically displace a reference object slightly outwards from the aligned row after a predetermined number of envelopes. The length of the row segment (corresponding to the required number of envelopes) to be withdrawn and inserted manually into the respective box is thus indicated to the operator.

[0004] The object of the present invention is to mechanize and automate said withdrawal of batches of objects from said manufacturing machines, so that these batches can be transferred for example into respective packaging boxes, in order to obtain the well known advantages deriving from mechanization and automation of operations.

[0005] Said object is attained by the invention as characterised in the claims.

[0006] The invention is described in detail hereinafter with the aid of the accompanying figures which illustrate a preferred but not exclusive embodiment thereof.

[0007] Figure 1 is a schematic side view of the entire machine of the invention. Figure 2 is a plan view of part of the machine of Figure 1, in which the gripper means 40 are not represented in order to illustrate other elements. Figure 3 is a section on the line III-III through the means illustrated in Figure 2, but in which the members 21 and 22 are shown close to each other in their rear end position. Figure 4 is a general section through the rod of the element 11. Figure 5 is a plan view of Figure 1 in which the gripper means 40 are not represented in order to illustrate other elements. Figures 6, 7, 8 and 9 are schematic views of some details of the machine during successive stages of operation; Figures 6 and 7 being plan views and Figures 8 and 9 being side views such as Figure 1.

[0008] The machine according to the invention comprises an endless conveyor which advances the objects in a single continuous row in which they are orientated substantially vertically and transversely on the conveyor surface.

[0009] It also comprises a parting means consisting of two elongate elements 11′ and 11˝ which when alongside each other define a pointed rod 11, in particular of circular cross-section, which is disposed with its axis horizontal and transverse to the direction of the conveyor 30, and passing through the row 2 of objects approximately in the centre thereof.

[0010] There are also provided means 10 for inserting the pointed end of the rod 11 axially through the row 2 of objects, and means 20 for moving the two elements 11′ and 11˝ together and apart parallel to each other in a longitudinal direction, to define a gap which separates an end segment 2′ of the row from the remaining portion 2˝ of the row under formation. The described means are coordinated and operated by known drive means (not shown in the figures and not further described as they are of known type) in such a manner that the machine effects the following operations automatically and cyclically in succession: inserting the rod 11 through the row 2, and moving the two elements 11′ and 11˝ apart to withdraw the elements 3 from each other and define said gap; moving gripper means 40 towards the upper surface of the conveyor 30, inserting a jab 41 into said gap and the other jaw 42 close to but slightly downstream of the end segment 2′; extracting the elongate elements 11′ and 11˝ from the row 2; clamping the jaws 41 and 42 against the segment 2′ and transferring this latter.

[0011] Specifically, the conveyor 30 comprises a fixed horizontal upper table 31 on which there supportedly slide two adjacent belts 32 passing endlessly about a driven drum 33 downstream and a drum 34 upstream. The upper surface of the belts 32 defines the upper surface of the conveyor 30 on which the objects 3 such as envelopes rest, and is preferably a surface with a fairly high coefficient of friction, such as of rubbery or knurled material. The means 10 comprise a box frame 12 rigidly fixed to a side wall of the supporting structure of the conveyor 30, which carries two horizontal cylindrical guides 13 extending transversely to the direction of advancement of the conveyor 30. A carriage 14 slides along the guides 13, a pneumatic cylinder-piston unit 15 being provided to drive the carriage 14 forwards and backwards along the guides 13.

[0012] The means 20 comprise a member 21 rigid with the carriage 14 and supporting the elongate element 11˝, and a second member 22 which supports the other element 11′. The member 22 is slidable along two horizontal guides 23 extending longitudinally (ie parallel to the direction of advancement of the conveyor 30) and carried by the carriage 14. Finally, a pneumatic cylinder-piston unit 24, the cylinder of which is rigid with the carriage 14, drives the support member 22 along the guides 23. By means of a bracket 16 the frame 12 supports a horizontal transverse cylinder-piston unit 17 carrying at the end of its rod a vertical longitudinal flat element 18 arranged to make contact with a side surface of the row 2. On the opposite vertical side of the row 2 there is a fixed longitudinal guide 19 (shown only in Figure 4) to keep the objects aligned in a row. The element 18 is normally a small distance from the side of the row 2 and is urged against this side only when the elements 11′ and 11˝ are extracted from the row 2. The body of the rod 11 is of cylindrical form and is divided longitudinally into two complementary parts which define the two elements 11′ and 11˝. The point is however not divided and is integral with one of the elements 11′ or 11˝. The preferred embodiment (shown in Figure 4) is that in which the element 11′ has a cross-section in the form of a circular sector with an angle of less than 180° at its centre, and the element 11˝ has a complementary cross-section. To support the advancing end face of the row 2 there is provided a support means 50 against which the downstream end object 3′ of the row 2 rests in a vertical position. Specifically, the means 50 comprises a base member 51 which rests by its own weight on the upper surface of the belts 32 and is retained on these by friction. Two vertical lateral flat elements 52 are fixed to the member 51, their upstream vertical edges acting as a support element for the end object 3′. The two elements 52 are spaced apart in a transverse direction to define a space into which the downstream jaw 42 can be inserted. The means 50 moves downstream together with the end object 3′ and with the face of the row 2, conveyed by the belts 32, until it reaches a downstream end-of-travel position. Each time the gripper means 40 remove a row segment 2′, the means 50 returns to its upstream travel commencement position to support the downstream end object 3˝ of the remaining row portion 2˝ (position shown in Figure 9).

[0013] For this purpose, to transfer the means 50 there is provided below the table 31 a pneumatic cylinder-piston unit 53 having its rod 54 parallel to the direction of the conveyor 30 and extending through the entire distance travelled by the support means 50. To the base 51 there is connected a bored member 55 which extends downward below the the table 31 and through which the rod 54 slidingly passes. The rod 54 is normally extended, and when the means 50 moves downstream the member 55 slides freely along the rod 54. At the end of the rod 54 there is a stop element 56 for the bored member 55, so that when the rod 54 has reached its retracted position, the means 50 has been transferred to the travel commencement position (shown by dashed lines in Figure 2 and full lines in Figure 9). The upper table 31 is provided with a longitudinal slot 57 of a length substantially equal to the length of the rod 54, and through which the bored member 55 passes and can freely slide.

[0014] There are also provided vertical elements 60 which retract below the surface of the conveyor 30 and are arranged to be inserted into the gap defined by the elongate elements 11′ and 11˝ to the side and upstream of the jaw 41 to temporarily act as a support for the remaining row portion 2˝ when the elements 11′ and 11˝ are extracted from the row. Specifically, the elements 60 are in the form of thin rods slidable in respective guide members 61 fixed to the side walls 35 of the conveyor 30, in such a manner as to be able to project upwards beyond the upper surface of the conveyor 30, to the sides of the belts 32.

[0015] The lower ends of the rods 60 are fixed to a small horizontal cross-member 62 driven by a pneumatic cylinder-piston unit 63, the cylinder of which is rigidly fixed to a frame 64 fixed to the side walls of the conveyor 30. On operating the cylinder-piston unit 63 the rods 60 rise beyond the upper level of the conveyor 30, whereas when the cross-member 62 is lowered the rods 60 are extracted from the row. The gripper means 40 comprise a mechanism 43, substantially of known type and not further described, for moving the jaws 41 and 42 symmetrically towards and away from each other. The jaws 41 and 42 lie more or less vertically, parallel to the planes in which the objects 3 lie, and slightly converge towards each other downwards. Suitable means are provided to lower, raise and transfer the means 40. The operation of the machine according to the invention is as follows.

[0016] The row 2 is formed by virtue of the fact that upstream of it a machine 4, for example for manufacturing envelopes, discharges said objects vertically onto the belts 32. As the machine 4 discharges the envelopes, the row 2 gradually increases in length and the conveyor 30 correspondingly moves downstream to advance with the row under formation. The end face of the row 2, defined by the downstream end object 3′, is supported by the means 50 which rests on the belts 32 and advances rigidly therewith and with the row 2.

[0017] The carriage 14 is normally at rest in a retracted position and the two members 21 and 22 are close together. The two elements 11′ and 11˝ are consequently alongside each other to define a single rod 11, which is in its extracted position, ie outside the row 2. The elements 60 are in their lowered position below the upper surface of the conveyor 30, and the gripper means 40 are above the row 2 (this stage being shown in Figure 5). When the end of the row 2 has passed downstream beyond the position of the rod 11 by a predetermined number of objects or by a predetermined length, the cylinder-piston unit 15 is operated to urge the carriage 14 forwards so as to insert the rod 11 through the row 2. As the rod 11 is pointed, it inserts by sliding between two adjacent objects and therefore without disturbing the row or damaging the objects. In all cases the fixed guide 19 keeps the objects reliably aligned and opposes any transverse thrusts 30 produced by the rod 11.

[0018] If a device (of known type and not shown in the figures) for cyclically displacing an object 3a slightly outwards from the aligned row after a predetermined number of objects (as shown in Figure 5) is provided, the rod 11 when in its extracted position is disposed with its point a short distance from a vertical side of the row 2, this distance being such that the point can intercept the projecting edge of the object 3a when this, advancing with the row, is in a position corresponding with the point. In this case, the rod 11 is inserted through the row 2 slightly after the object 3a has rested against the point of the rod 11 (as shown in Figure 6). In this manner, between the object 3a and the downstream adjacent object a gap is created in which the point of the rod 11 is already disposed, this facilitating and ensuring the insertion of the rod 11 through the row 2 (the insertion taking place between the object 3a and the adjacent downstream object). To trigger the introduction of the rod 11, a proximity sensor 25 can be provided close to the side of the row 2 below the point of the rod 11 to indicate the presence of the reference object 3a.

[0019] To return the object 3a into exact alignment with the other objects 3 of the row there is provided a member 26 fixed to the carriage 14 and projecting forwards from it so that its front edge is aligned and in contact with the lower edge of the objects 3 when the carriage 14 is in its fully advanced position. Consequently, during the forward movement of the carriage 14, the member 26 urges the reference object 3a into the row 2 to bring it into perfect alignment. Immediately after the insertion of the rod 11 the cylinder-piston unit 24 is operated to move the elements 11′ and 11˝ apart in the longitudinal direction in order to create a gap which separates the end row segment 2′ (between the downstream end object 3a and the object adjacent to the object 3a in a downstream direction) from the remaining upstream portion 2˝ (the face 3˝ of which is defined by that object 3a which initially acted as the reference object) (stage shown in Figure 7). The elements 11′ and 11˝ separate by leaving the element 11˝ at rest and moving the element 11′ downstream. Consequently the row segment 2′ is also moved slightly downstream, with the objects 3 and the support means 50 sliding on the surface of the belts 32. The cylinder-piston unit 63 is then operated to raise the elements 60 so that they project into the gap created by the elements 11′ and 11˝, to a height approximately equal to the height of the objects 3. More or less simultaneously with these operations, the support means 50 strikes the element 56 and halts thereat. Immediately afterwards, the gripper means 40 descend from above and approach the upper surface of the conveyor 30, to insert the jaw 41 into said gap downstream of the vertical elements 60 but upstream of the element 11′, and to insert the jaw 42 downstream of the end object 3′ into the space defined between the elements 52 of the means 50 (as shown in Figure 1 and Figure 8). Immediately afterwards, the carriage 14 is withdrawn to extract the elements 11′ and 11˝ from the row. As these no longer provide support, the objects 3 rest against the jaw 41 and against the vertical elements 60. Immediately prior to this extraction the flat element 18 is moved against the side of the row 2 to ensure that during extraction, the elements 11′ and 11˝ are unable to drag the objects 3 with them.

[0020] At this point the jaws 41 and 42 of the means 40 are moved towards each other to tightly grip the row segment 2′ and then remove this segment 2′ from conveyor 30, for example to insert it into a packaging box. Immediately afterwards, the cylinder-piston unit 53 retracts its rod 54 to transfer the support means 50 into contact with the end object 3˝ of the portion 2˝ (as shown in Figure 9). The objects therefore remain resting against the elements 52, and consequently the vertical rods 60 are withdrawn downwards. At this point the end face 3˝ of the row (which now defines said face 3′) again advances downstream supported by the means 50, which now advances resting on the belts 32, and the cycle recommences as heretofore described.

[0021] To automate the machine movements, suitable control, regulating and operating means (of known type and not shown) are provided and are coordinated synergically by a suitable control centre. By virtue of its structural and operational characteristics the machine of the invention is capable of a high production rate, is completely automatic and provides high operational reliability. Numerous modifications of a practical and applicational nature can be made to the invention but without 1 eaving the scope of the inventive idea as hereinafter claimed.

Claims

1. A machine for withdrawing predetermined batches of flat objects such as envelopes or sheets of paper from a continuously forming row, comprising an endless conveyor (30) for advancing the objects (3) in a single continuous row in which they are orientated substantially vertically and transversely on the upper surface of the conveyor (30), characterised by comprising:
- a parting means consisting of two elongate parallel elements (11′) and (11˝) which when alongside each other define a pointed rod (11), said rod (11) being disposed on an axis transverse to the direction of the conveyor (30) and passing through the row (2) of object 3;
- means (10) for inserting the pointed end of said rod (11) axially through the row (2) of objects;
- means (20) for moving the two elongate elements (11′) and (11˝) together and apart parallel to each other in a longitudinal direction, to define a gap which separates an end segment (2′) of the row from the remaining row portion (2˝);
- gripper means (40) comprising two jaws (41) and (42) for gripping said end row segment (2′);
- the machine effecting the following operations automatically and cyclically in succession: inserting the pointed rod (11) through the row (2) between two objects (3) thereof; moving the two elongate elements (11′) and (11˝) apart to define said gap; moving the gripper means (40) towards the upper surface of the conveyor (30) to insert one jaw (41) into said gap and the other jaw (42) close to but slightly downstream of the end object (3′) of the row segment (2′); extracting said long elements (11′) and (11˝) from the row (2); clamping the jaws (41) and (42) against the row segment (2′) and transferring this latter.

2. A machine as claimed in claim 1, characterised by comprising: a support means (50) against which the downstream end object (3′) of the row (2) supportedly rests in a vertical position, said means (50) advancing downstream simultaneously with said end object (3′); means for transferring the support means (50) upstream to its travel commencement position to support the downstream end object (3˝) of the remaining row portion (2); said support means (50) advancing downstream simultaneously with said end object (3′) and being returned to its travel commencement position after each time that the gripper means (40) have removed a row segment (2′).

3. A machine as claimed in claim 2, characterised in that: said support means (50) comprises a base member (51) which rests on the upper mobile surface of the line of advancement (30), on which it is retained by friction; two vertical lateral flat elements (52) fixed to the member (51) and having their upstream vertical edges acting as a support element for the end object (3′), (3˝); between the two flat elements (52) there being defined a space into which a jaw of the gripper means can be inserted; and said means or transferring the support means (50) comprise a fluid-operated cylinder-piston unit (53) having its rod (54) parallel to the direction of the conveyor (30) and extending through the entire distance travelled by the support means (50); a bored member (55) fixed to the support means (50) and through which said rod (54) slidingly passes; said rod (54), provided at its end with a stop element (56) for the member (55), being normally extended and being moved into its retracted position to transfer the support means (50) to its travel commencement position.

4. A machine as claimed in claim 2, characterised by comprising vertical elements (60) which retract below the surface of the conveyor (30) and are arranged to be inserted into the gap defined by the elongate elements (11′) and (11˝) to the side and upstream of the jaw (41) to temporarily act as a support for the remaining row portion (2˝) when said elongate elements (11′) and (11˝) are extracted from the row; said vertical elements (60) being extracted from the row (2) after said support means (50) has been returned to its travel commencement position.

5. A machine as claimed in claim 1, characterised in that: the means (10) for inserting the pointed rod (11) comprise: a frame (12) rigid with the conveyor (30); horizontal transverse guides (13) carried by said frame (12); a carriage (14) slidable along said guides (13); means (15) for driving said carriage (14) along the guides (13);
the means (20) for moving the two elongate elements (11′) and (11˝) apart and together comprise: a support member (21) for an elongate element (11˝), rigid with said carriage (14);
longitudinal horizontal guides (23) carried by said carriage (14); a second support member (22) for the other elongate element (11′) and slidable along said longitudinal guides (23); means (24) for driving said second support member (22) along the guides (23).

6. A machine as claimed in claim 1, characterised in that the body of the pointed rod (11) is divided longitudinally into two complementary parts which define two elongate elements (11′) and (11˝), the point of the rod (11) being whole and bein integral with only one element (11′) or (11˝).

7. A machine as claimed in claim 5, characterised by comprising a longitudinal vertical flat element (18) arranged to make contact with a vertical side of the row (2) when the elongate elements (11′) and (11˝) are extracted from the row.

8. A machine as claimed in claim 1, of the type in which a device for cyclically displacing a reference object slightly outwards from the aligned row after a predetermined number of objects is provided, characterised in that said pointed rod (11) when in its extracted position is disposed with its point a short distance from a vertical side of the row (2), such as to intercept the projecting edge of the reference object (3a), the rod being inserted through the row shortly after the reference object (3a) advancing on the conveyor (30) rests against the point of the rod (11).

9. A machine as claimed in claims 1, 3 and 4, characterised by effecting the following operations automatically and cyclically in succession: inserting the pointed rod (11) through the row (2) between two objects (3) thereof and moving the two elements (11′) and (11˝) apart to define a gap; inserting the vertical elements (60) into the gap defined by the elements (11′) and (11˝);
lowering the gripper means (40) to insert the jaw (41) into said gap downstream of the vertical elements (60) and insert the other jaw (42) downstream of the row end segment (2′) into the space defined between the flat elements (52); extracting the elements (11′) and (11˝) from the row (2); moving the jaws (41) and (42) towards each other and removing the row segment (2′) from the conveyor (30); transferring the support means (50) upstream to support the end object (3˝) of the remaining row portion (2˝); withdrawing the vertical elements (60) downwards.

Drawing